Method for dampening projector vibration

ABSTRACT

The disclosure is directed toward stabilizing an image projected by a projector in an environment including vibrations or other movements that displace the projected image. In one set of implementations, an image projected by a projector may be stabilized by using an image stabilization system that detects a displacement of the projector from an equilibrium position and controls an optical element of the projector to offset the displacement. In an additional set of implementations, an image projected by the projector may be stabilized by using an image stabilization system that measures a rate of displacement from equilibrium of an image projected by the projector to predict a displacement of the projector and counteract the predicted displacement. In another set of implementations, an image projected by a projector may be stabilized by precalculating a plurality of lookup tables that correct for displacements of the projected image during operation of the projector.

BRIEF SUMMARY OF THE DISCLOSURE

The disclosure describes improved systems and methods for eliminating ormitigating vibrations or other unwanted movements introduced into aprojector.

In one example, a system includes: an image stabilization system,including: one or more motion sensors to measure a total displacement ordisplacement rate of an image projected by a projector from anequilibrium position; and a processing unit to cause one or moreactuators of the projector to actuate an optical element of theprojector to stabilize the projected image, where the optical element isactuated using at least the measured total displacement or displacementrate. In some implementations, the system also includes the projector,and the projector includes: a light source; one or more optical elementsto structure light emitted by the light source to create the image; anda projection lens to project the image. In implementations, theprojector includes the image stabilization system and/or the motionsensors.

In some implementations, the one or more motion sensors are to measurethe total displacement of the projected image from equilibrium, and theoptical element is actuated using at least the measured totaldisplacement.

In some implementations, the system includes: a memory storing aplurality of lookup tables, each of the plurality of lookup tablesconfigured to correct a respective displacement or displacement range ofa projected image, where the processing unit causes the one or moreactuators to actuate the optical element using at least a lookup tablecorresponding to the measured total displacement.

In some implementations, the one or more actuators include a motor toactuate the projection lens to correct for the measured displacement ofthe projected image.

In some implementations, the projector is a digital light processing(DLP) projector including a digital micromirror device (DMD) chipcomprising a plurality of mirrors, where processing unit causes the oneor more actuators are to actuate the plurality of mirrors to correct forthe measured displacement of the projected image.

In some implementations, the projector is a liquid crystal display (LCD)projector including an LCD panel, where the processing unit causes theone or more actuators to actuate the LCD panel to correct for themeasured total displacement of the projected image.

In some implementations, the projector is a liquid crystal on silicon(LCoS) projector including a LCoS microdevice, where the processing unitcauses the one or more actuators to actuate the LCoS microdevice tocorrect for the measured total displacement of the projected image.

In some implementations, the image stabilization system is a three-axisimage stabilization system, where the one or more motion sensors measuredisplacement of the projected image in three axes.

In some implementations, the one or more motion sensors are to measurethe rate of displacement of the projected image from equilibrium, andthe processing unit causes the one or more actuators to actuate theoptical element of the projector to correct for a predicted displacementof the projected image using at least the measured rate of displacement.

In some implementations, the one or more motion sensors are to measurethe total displacement and the rate of displacement of the projectedimage from equilibrium, and the processing unit causes the one or moreactuators to actuate the optical element of the projector to correct fora predicted displacement of the projected image using at least themeasured rate of displacement and measured total displacement.

In another example, a method includes: using one or more motion sensorsto measure a total displacement from an equilibrium position of an imageprojected by a projector; using at the least the measured totaldisplacement, determining an actuation of an optical element of theprojector to stabilize the image; and stabilizing the projected image byactuating the optical element. In some implementations, the opticalelement is actuated based on a precalculated lookup table associatedwith a map to correct for the measured total displacement, where thelookup table is stored in a memory of the projector.

In some implementations, the method further includes: storing aplurality of lookup tables in a memory of the projector, each of theplurality of lookup tables associated with a map to correct a respectivedisplacement or displacement range of a projected image.

In some implementations, the method further includes: determining if themeasured total displacement exceeds a predetermined threshold.

In another example, a method includes: using one or more motion sensorsto measure a rate of displacement from an equilibrium position of animage projected by a projector; using at the least the measured rate ofdisplacement, estimating an actuation of an optical element of theprojector to maintain a stabilized image; and actuating the opticalelement based on the estimated actuation.

Other features and aspects of the disclosed method will become apparentfrom the following detailed description, taken in conjunction with theaccompanying drawings, which illustrate, by way of example, the featuresin accordance with embodiments of the disclosure. The summary is notintended to limit the scope of the claimed disclosure, which is definedsolely by the claims attached hereto.

It should be appreciated that all combinations of the foregoing concepts(provided such concepts are not mutually inconsistent) are contemplatedas being part of the inventive subject matter disclosed herein. Inparticular, all combinations of claimed subject matter appearing at theend of this disclosure are contemplated as being part of the inventivesubject matter disclosed herein.

BRIEF DESCRIPTION OF THE DRAWINGS

The present disclosure, in accordance with one or more implementations,is described in detail with reference to the following figures. Thefigures are provided for purposes of illustration only and merely depictexample implementations. Furthermore, it should be noted that forclarity and ease of illustration, the elements in the figures have notnecessarily been drawn to scale.

Some of the figures included herein illustrate various implementationsof the disclosed technology from different viewing angles. Although theaccompanying descriptive text may refer to such views as “top,” “bottom”or “side” views, such references are merely descriptive and do not implyor require that the disclosed technology be implemented or used in aparticular spatial orientation unless explicitly stated otherwise.

FIG. 1 illustrates an example system including a projector with whichembodiments of the disclosure may be implemented.

FIG. 2 illustrates an individual picture element of an image projectedby a projector before displacement of the projector.

FIG. 3 illustrates the individual picture element of FIG. 2 afterdisplacement.

FIG. 4 illustrates the expected range of displacement of the pictureelement of FIG. 2 during operation of the projector, where the expectedrange is illustrated as a gray area varying in intensity.

FIG. 5 is an operational flow diagram illustrating an examplepixel-shifting method to stabilize an image projected by a projector byoffsetting the projected image depending on a detected displacement ofthe projector.

FIG. 6 shows Y-axis and X-axis displacement of a projected image thatmay occur during operation of a projector.

FIG. 7 is a graph depicting the displacement of a projector's housing inone dimension as a function of time in response to vibrations.

FIG. 8 is an operational flow diagram illustrating an examplepixel-shifting method to stabilize an image projected by a projector byoffsetting the projected image using a predicted displacement based on ameasured rate of displacement of the projected image.

FIG. 9 shows a first plot depicting one-axis movement of a projectedimage from equilibrium as a function time, and a second plot depictingone-axis predicted cancellation movement of the projected image as afunction of time.

FIG. 10 is an operational flow diagram illustrating an example method tostabilize a projected image by precalculating a plurality of lookuptables that correct for image displacements of the projector duringoperation.

FIG. 11 shows a measured average range-of-motion of a projected pictureelement before compensation and after compensation.

FIG. 12 illustrates a portion of a projected film frame as would beperceived by a viewer before correction, and a portion of the projectedfilm frame as would be perceived by viewers after application of one ormore precomputed LUTs.

FIG. 13 illustrates a chip set/computing module 90 in which embodimentsof the technology disclosed herein may be implemented.

The figures are not exhaustive and do not limit the disclosure to theprecise form disclosed.

DETAILED DESCRIPTION

Video projectors act to amplify vibrations due to an effect of the lensspreading light from a small aperture to a much larger surface. Becausethe screen area where a projector projects may be many times larger thana projector's emission surface, vibrations may be proportionallymagnified in the projected image as well.

The above problem is particularly noticeable when a projector isrequired to operate in settings with many sources of vibration such asstage performances, theme parks, movie sets, and the like. For example,vehicles used in theme parks and stages, and wenches used to hoistdifferent props on stage may be necessary components of a stageperformance, movie production, or theme park ride, but may alsointroduce significant sources of noise that cause vibration of an activeprojector. When the display device undergoes displacement, the vibrationof the image projected by the projector may be particularly noticeable.In such settings, the vibrational problem generally cannot be solved bymoving the projector to a different location or operating the projectorwhen there is no noise or other source of vibration. Rather, it may benecessary to operate the projector with these sources of vibrationpresent.

Present methods for addressing this method focus on mechanicallymounting and isolating the projector in such a manner that limits thetransfer of forces to the projector that induce displacement of theprojector from equilibrium and destabilization of the projected image.For example, present methods may focus on isolating the projector fromvibrational sources such as noise, temperature gradients, etc. Suchmethods may introduce expenses and construction. For example, aprojector may need to be equipped with vibration isolators to preventforces that induce vibration from reaching the projector.

To this end, the disclosure describes improved systems and methods foreliminating or mitigating vibrations or other unwanted movementsintroduced into a projector. In accordance with one set ofimplementations, an image projected by a projector may be stabilized byusing an image stabilization system that detects a displacement of theprojector and actuates an optical element of the projector to offset thedisplacement.

In accordance with an additional set of implementations, an imageprojected by the projector may be stabilized by using an imagestabilization system that measures a rate of displacement fromequilibrium of an image projected by the projector to predict adisplacement of the projector and counteract the predicted displacement.In these implementations, a method may include: measuring the rate ofdisplacement, using at the least the measured rate of displacement,estimating an actuation of an optical element of the projector requiredto maintain a stable image, and actuating the optical element.

In accordance with another set of implementations, an image projected bya projector may be stabilized by precalculating a plurality of lookuptables that correct for displacements of the projected image duringoperation of the projector. After precalculating the plurality of lookuptables, the projector's image may be stabilized during operation bydetecting displacement from equilibrium of the image projected by theprojector, and applying one of the plurality of precalculated lookuptables to the projected image to correct for displacement. These andother implementations are further described below.

FIG. 1 illustrates an example system including a projector 100 withwhich embodiments of the disclosure may be implemented. As illustrated,projector 100 uses a projection lens 130 to project an image ontoprojection surface 190 during operation. For example, projection surface190 may be a screen, a wall, a floor, an object surface, or some othersurface onto which an image is projected. Projector 100 may be anysuitable projector for the environment, such as, for example, a digitallight processing (DLP) projector, a liquid crystal on silicon (LCoS)projector, a liquid crystal display (LCD) projector, a laser scanningprojector, or other projector.

Projector 100 may operate in an environment that includes forces thatdisplace the projector 100 from equilibrium, thereby inducing vibrationsthat may displace the image projected by projector 100. This isillustrated by FIGS. 2-4, which show the potential displacement of aprojected individual picture element 200 (e.g. a pixel) of a projectedimage 250 from vibration of projector 100. FIG. 2 shows the individualpicture element before displacement. FIG. 3 shows the individual pictureelement 200 after it is displaced by movement. FIG. 4 shows a gray area400 varying in intensity that depicts the expected displacement ofpicture element 200 due to vibration or some other movement of projector100. As would be appreciated from the foregoing illustrations, inaddition to causing the projected image to move, vibrations or otherdisplacements of the projected image may also cause the projected imageto appear blurry to a human viewer.

In accordance with implementations, further described below, projector100 may be configured to prevent or correct image displacement duringprojection (i.e., “stabilize” the projected image). As illustrated,projector 100 may include: a light source 110, one or intermediaryoptical elements 120, a projections lens 130, one or more processingmodule(s) 140, a memory 150, one or more motion sensor(s) 160, and acontroller 170 to control one or more actuators 175. Projector 100 mayalso include an input (not shown) for receiving a digital source signal(e.g., a digital image or video to be projected).

Light source 110 may comprise one or more of an incandescent lightsource (e.g., an ultra-high pressure lamp), a light emitting diode(LED), a laser, or other suitable light source. Intermediary opticalelements 120 may be configured to structure light emitted by the lightsource to create an image. For example, in the case of a single-chip DLPprojector, intermediary optical elements 120 may include: opticalelements to route the light (e.g., mirrors), a rotating color wheel, anda digital micromirror device (DMD) chip comprising a matrix (e.g.,microarray) of movable mirrors to reflect light. For example, each ofthe movable mirrors may correspond to a pixel of a projected image. Inthe case of a three-chip DLP projector, intermediary optical elements120 may include: optical elements to route the light, an optical elementto split light into three primary colors (e.g., dichroic mirrors orprism), three DMD chips, each configured to receive a respective colorof light (e.g., red, green, and blue), and an optical element forrecombining the output of each of the DMD chips.

As another example, in the case of an LCD projector, intermediaryoptical elements 120 may include optical elements such as mirrors toroute the light, optical elements to split light into three primarycolors (e.g., dichroic mirrors or prism), three transmissive LCD panelsor displays (e.g., plurality of optical cells or pixels includingpolarizing filters and liquid crystal layer) to receive a respectivecolor component (e.g., red, green, or blue) of an image signal, a lightrecombiner (e.g., a dichroic prism to recombine light from the LCDpanels), and other elements.

As a further example, in the case of an LCoS projector, intermediaryoptical elements 120 may include optical elements to route the light,optical elements to split light into three primary colors (e.g.,dichroic mirrors or prism), three reflective LCoS microdevices (e.g.,liquid crystal layer between thin-film transistor and siliconsemiconductor) to receive a respective color component (e.g., red,green, or blue) of an image signal, a light recombiner, and otherelements.

Projection lens 130 may collect and focus light from intermediaryoptical elements 120 to project an image on a surface 190. For example,in the case of a DLP projector, projections lens 130 may project andfocus light from a DMD chip or recombined light from three DMD chipsonto a projection surface. As another example, in the case of an LCDprojector, projection lens 130 may project and focus recombined lightfrom three LCD panels onto a projection surface.

Processing module(s) 140 may comprise circuitry for decoding a digitalsource signal (e.g., a digital video), circuitry for processing signalsreceived from one or more motion sensor(s) 160, and/or circuitry forcontrolling optical components of the projector to project an imagebased on a received source signal and signals received from motionsensor(s) 160.

One or more processing module(s) 140, motion sensor(s) 160 andactuator(s) 175 may be components of an image stabilization system ofprojector 100. Motion sensor(s) 160 may generate electronic signalsrepresentative of the motion or position of projector 100. Theseelectronic input signals may be received and processed by circuitry of aprocessing module 140 during operation to determine an absoluteorientation the projector, determine an amount of displacement from theequilibrium position of the projector (i.e., position where there are novibrations/movement), and/or determine a rate of displacement of theprojector. In implementations, the one or more motion sensor(s) maymeasure displacement along three axes (e.g., pitch, yaw, and rolldirections). In various implementations, motion sensor 160 may compriseone or more gyroscopes, accelerometers, and magnetometers that mayoperate in one or more axes. For example, motion sensor(s) 160 maycomprise a 3-axis accelerometer. The motion sensors 160 may be mountedon a projector housing, surfaces of the projector containing the lightpath, and/or some other suitable location for measuring an amount ofdisplacement or rate of displacement of the projected image.

Actuators 175 may comprise motors, microelectromechanical system (MEMS)actuators, piezoelectric actuators, translation stages, or some otheractuator that may actuate (e.g., translate or rotate) or otherwiseconfigure an optical element of projector 100 in one or more axes tocorrect for or prevent image displacement. In some cases, actuators 175may be components that control the positioning or configuration ofoptical elements of projector 100 to project an image when imagestabilization is not applied. In such cases, actuators 175 may beconfigured to apply a modified control of the optical elements (e.g.,one taking into account the displacement of a projected image) whenimage stabilization is applied.

Memory 150 may comprise volatile memory (e.g. RAM), non-volatile memory(e.g. flash storage), or some combination thereof. In variousimplementations, memory 150 may store machine readable instructions,that when executed by a processing module 140 (e.g., a digital signalprocessor), cause projector 100 to correct for or prevent imagedisplacement during projection. For example, execution of the machinereadable instructions may cause processing module(s) 140 to processreadouts by motion sensors 160 to determine a total amount ofdisplacement from equilibrium in one or more axes (e.g., 3 axes) and/ordetermine a rate of displacement in one or more axes (e.g., 3 axes).Additionally, execution of the machine readable instructions may causeprocessing module(s) to cause controller 170 to send one or more controlsignals to actuator(s) 175 to actuate one or more optical elements ofthe projector to correct for or prevent image displacement based on theprocessed readouts by motion sensors 160. Memory 150 may also store ahistory of processed motion sensor readouts (e.g., displacement and rateof displacement data) and/or lookup tables that may be used to correctfor displacement during projection.

FIG. 5 is an operational flow diagram illustrating an examplepixel-shifting method 500 to stabilize an image projected by a projectorby offsetting the projected image depending on a detected displacementof the projector. For example, method 500 may be implemented tocounteract the effects of vibration on a projector 100 by using an imagestabilization system including one or more processing module(s) 140,motion sensor(s) 160, controller 170, and/or actuator(s) 175.

At operation 510, one or more motion sensors of a projector are used todetect and measure a displacement from equilibrium of an image projectedby the projector. In implementations, a reference equilibrium positionof the projector may be established by the one or more motion sensors(e.g., sensors 160) when there are no vibrations or other forces thatcause movement of the projector. The displacement may be detected in oneaxis, two axes, or three axes. By way of illustrative example, FIG. 6shows both a Y-axis and X-axis displacement of a projected image thatmay occur during operation of the projector. In example FIG. 6, theshaded black picture element shows a displaced picture element and theshaded gray picture element in the background shows the desired positionof the picture element. In implementations, a displacement detected by amotion sensor such as an accelerometer may be converted to acorresponding pixel displacement (e.g., ½pixel, 1 pixel, 2 pixels, 4pixels, etc.) using a precomputed mapping between motion sensor detecteddisplacement and corresponding pixel displacement.

At decision 520, it is determined whether the measured displacementexceeds a predetermined threshold. For example, in some implementationsit may not be necessary to correct for the displacement if it is notperceptible by the human eye (e.g., does not introduce a perceptibleblur or movement of the projected image). In some implementations, apredetermined threshold may be compared to the measured displacement ineach of multiple directions (e.g., x direction and y direction).Additionally, in some implementations, the threshold may be configuredas the smallest displacement an image stabilization system of theprojector can correct. In alternative implementations, decision 520 maybe skipped.

At operation 530, based on the measured displacement, a processingsystem or unit of the projector may calculate an actuation orconfiguration of an optical element of the projector necessary tostabilize the projected image (e.g., to counteract the displacement). Atoperation 540, the projected image may be stabilized by actuating orconfiguring the optical element of the projector to alter or reinterpretan optical path in the projector (e.g., in pitch, yaw, and rolldirections) based on the calculated actuation or configuration. Forexample, if a displacement of +2 pixels in the x-axis and −3 pixels inthe y-axis is detected, the projected image may be displaced −2 pixelsin the x-axis and +3 pixels in the y-axis.

In some implementations, the projected image may be stabilized by usingan actuator to actuate the projections lens (e.g. projection lens 130)of the projector to cancel movement of the projected image. In otherimplementations, an intermediary optical element (e.g., element 120) ofthe projector may be actuated. For example, in the case of a DLPprojector, the mirrors of one or more DMD chips may be moved to changethe angle at which light is reflected. In the case of an LCD projectoror LCoS projector, the LCD panels or LCoS panels may be translated. Inother implementations, the optical path of some other element of theprojector may be varied to compensate for projector movement.

Method 500 may be iteratively repeated to dynamically compensate fortime-varying displacements (e.g., varying vibrations) to maintain astable image. For example, as illustrated by FIG. 7, which is a graphdepicting the displacement of a projector's housing in one dimension asa function of time, there may be significant variations in thedisplacement over time. In implementations, the rate at which method 500is repeated may exceed a predetermined threshold. For example, thethreshold may exceed a frame rate of a projected video and/or a rate atwhich the stabilization becomes imperceptible to the human eye.

In particular implementations where the projector displays video,optical-flow analysis may be utilized to generateinterframe-displacement images if the projector is capable of displayingvideo frames at a higher rate than the frame rate of the video (e.g. 24FPS). In such implementations, each video frame may bedisplaced/repositioned one or more times at a rate higher than thevideo's frame rate (and thus displayed two or more times) withoutchanging the desired temporal appearance of the video. For example, eachvideo frame may be displaced at a rate that is some multiple n of theframe rate of the video, where n>1 and is an integer.

In some implementations, image stabilization of the projector may beachieved by predicting the displacement of the projected imaged based ona rate of change of the displacement (e.g., magnitude and direction ofdisplacement), and counteracting the predicted displacement. FIG. 8 isan operational flow diagram illustrating one such example method 800. Inparticular, FIG. 8 illustrates an example pixel-shifting method tostabilize an image projected by a projector by offsetting the projectedimage using a predicted displacement based on a measured rate ofdisplacement of the projected image. For example, method 800 may beimplemented to counteract the effects of vibration on a projector 100 byusing an image stabilization system including one or more processingmodule(s) 140, motion sensor(s) 160, controller 170, and/or actuator(s)175.

At operation 810, one or more motion sensors of a projector are used tomeasure a rate of displacement from equilibrium of an image projected bythe projector. In implementations, a reference equilibrium position ofthe projector may be established by the one or more motion sensors(e.g., sensors 160) when there are no vibrations or other forces thatcause movement of the projector. The rate of displacement may bedetected in one axis, two axes, or three axes, and may include amagnitude and direction of displacement from equilibrium. Inimplementations, a rate of displacement detected by a motion sensor suchas an accelerometer may be converted to a corresponding pixel rate ofdisplacement (e.g., ½pixel/second, 1 pixel/second, 2 pixels/second, 4pixels/second, etc.) using a precomputed mapping between motion sensordetected displacement and corresponding pixel displacement.

At operation 820, using at least the measured rate of displacement aprocessing system or unit of the projector may estimate an actuation orconfiguration of an optical element of the projector necessary tomaintain a stable projected image (e.g., to counteract the predicteddisplacement). By way of illustrative example, FIG. 9, shows a firstplot depicting stepwise, one-axis movement of a projected image fromequilibrium as a function time, and a second plot depicting stepwise,one-axis predicted cancellation movement of the projected image as afunction of time. Movement of the projector may be sampled at asufficient rate such that a cancellation movement may be reliablypredicted.

At operation 830, the optical element may be actuated or configuredbased on the estimated actuation to maintain a stable image. Forexample, as discussed above, a projection lens of the projector may beactuated, the mirrors of one or more DMD chips of a DLP projector may bemoved to change the angle at which light is reflected, the LCD panels ofan LCD projector may be reconfigured, or the LCoS panels of an LCoSprojector may be reconfigured.

Although methods 500 and 800 have so far been described as separatemethods for stabilizing an image projected by a projector, in someimplementations, the techniques of methods 500 and 800 may be combined.By way of example, the measured displacement position from equilibriumalong with the measured rate of displacement (e.g., magnitude anddirection) may both be considered in estimating an actuation of anoptical element needed to stabilize the projected image and/or maintaina stable projected image.

In some implementations, it may be advantageous to precalculate thepossible range of displacements of a projector during operation, andcreate a set of lookup tables (LUTs) to correct for displacements withinthe range of displacements. For example, each LUT may map the set ofpixels of a video frame from a first position to a second positiondepending on a measured displacement. In many cases, a projector mayoperate in an environment that repeatedly subjects it to the same orsimilar vibrational forces. For instance, consider a projector that ismounted on a wall near a track of a theme park ride. In this instance,the projector may repeatedly experience the same or similar vibrationalforces as vehicles running on the track approach and pass the projector.This may significantly limit the range or number of compensations thatneeded to be precalculated to correct for image displacement. Bymeasuring the displacements during one or more of these events, aplurality of lookup tables may be precalculated that account for all ofthe vibrational forces the projector generally experiences.Additionally, even if the vibrations of the environment are notconsistent, a projector may not move inadvertently in an unlimitedrange, which in itself may limit the number of compensations that neededto be precalculated.

FIG. 10 is an operational flow diagram illustrating one such examplemethod 1000 to stabilize a projected image by precalculating a pluralityof LUTs that correct for image displacements of the projector duringoperation. For example, method 1000 may be implemented to counteract theeffects of vibration of a projector 100 by using an image stabilizationsystem including one or more processing module(s) 140, motion sensor(s)160, controller 170, and/or actuator(s) 175.

At operation 1010, a range of displacements of the projector duringprojector operation may be measured. These displacements may be measuredin one axis, two axes, or three axes using one or motion sensors (e.g.,motion sensor(s) 160). By way of illustrative example, FIG. 11 shows ameasured average range-of-motion of a projected picture element beforecompensation (scenario 1110) and after compensation (scenario 1120). Inthis example, a gray area 1115 varying in intensity depicts the measureddisplacement of the picture element due to vibration or some othermovement.

At operation 1020, using the measured range of displacements, aplurality of LUTs may be precalculated, where each LUT may calculated tocorrect for a displacement or range of displacements of the projectedimage in one or more dimensions. For example, each LUT may contain anarray of values such as floating point numbers representing adisplacement correction for each of the pixels of the projected imagefor a measured displacement of the image. In implementations, each LUTmay contain a single correction that is applied to the entire image(e.g., all pixels are displaced by the same value) or amulti-dimensional correction that applies different displacementcorrections to different pixels depending on the positions of theprojected pixel.

At operation 1030, displacement of a projected image during operation ofthe projector may be measured using one or more motion sensors. Forexample, the displacement from equilibrium and/or displacement rate fromequilibrium may be measured as described above with reference to methods500 and 800.

At operation 1040, based on the measured displacement and/ordisplacement rate, one or more of the plurality of precalculated LUTsmay be applied to the projected image to stabilize the projected image.For example, the measured displacement and/or displacement rate may becompared to a displacement and/or a displacement rate (or displacementrange and/or displacement rate range) of the LUTs, and a matching ormost similar LUT may be used to stabilize the projected image. Agraphical processing unit (GPU) or other processing unit of theprojector may pre-read a LUT that is applied to a frame of a videosource file before the video frame is projected.

By way of example, FIG. 12 illustrates a portion 1210 of a projectedfilm frame 1200 as would be perceived by a viewer before correction, anda portion 1230 of the projected film frame as would be perceived byviewers after application of one or more precomputed LUTs 1220. Asillustrated, the LUTs 1220 may be applied on a per-frame basis. Beforecorrection, the projected film frame may appear blurred to a viewer, anddisplacement may be measured in two axes. Precomputed lookup tables 1220that correct the measured displacement may result in a corrected frame.

FIG. 13 illustrates a chip set/computing module 90 in which embodimentsof the technology disclosed herein may be implemented. Chip set 90 caninclude, for instance, processor, memory, and additional imagecomponents incorporated in one or more physical packages. By way ofexample, a physical package includes an arrangement of one or morematerials, components, and/or wires on a structural assembly (e.g., abaseboard) to provide one or more characteristics such as physicalstrength, conservation of size, and/or limitation of electricalinteraction.

In one embodiment, chip set 90 includes a communication mechanism suchas a bus 92 for passing information among the components of the chip set90. A processor 94, such as an image processor has connectivity to bus92 to execute instructions and process information stored in a memory96. A processor may include one or more processing cores with each coreconfigured to perform independently. Alternatively or in addition, aprocessor may include one or more microprocessors configured in tandemvia bus 92 to enable independent execution of instructions, pipelining,and multithreading. Processor 94 may also be accompanied with one ormore specialized components to perform certain processing functions andtasks such as one or more digital signal processors, e.g., DSP 98, suchas an OIS DSP, image sensor, OIS gyroscope, and/or one or moreapplication-specific integrated circuits (IC) (ASIC) 100, such as thatwhich can be utilized to, e.g., drive a MEMS actuator for achieving OIS,zoom, and/or AF functionality. DSP 98 can typically be configured toprocess real-world signals (e.g., sound) in real time independently ofprocessor 94. Similarly, ASIC 100 can be configured to performedspecialized functions not easily performed by a general purposedprocessor. Other specialized components to aid in performing theinventive functions described herein include one or more fieldprogrammable gate arrays (FPGA) (not shown), one or more controllers(not shown), or one or more other special-purpose computer chips.

The aforementioned components have connectivity to memory 96 via bus 92.Memory 96 includes both dynamic memory (e.g., RAM) and static memory(e.g., ROM) for storing executable instructions that, when executed byprocessor 94, DSP 98, and/or ASIC 100, perform the process of exampleembodiments as described herein. Memory 96 also stores the dataassociated with or generated by the execution of the process.

As used herein, the term module might describe a given unit offunctionality that can be performed in accordance with one or moreembodiments of the present application. As used herein, a module mightbe implemented utilizing any form of hardware, software, or acombination thereof. For example, one or more processors, controllers,ASICs, PLAs, PALs, CPLDs, FPGAs, logical components, software routinesor other mechanisms might be implemented to make up a module. Inimplementation, the various modules described herein might beimplemented as discrete modules or the functions and features describedcan be shared in part or in total among one or more modules. In otherwords, as would be apparent to one of ordinary skill in the art afterreading this description, the various features and functionalitydescribed herein may be implemented in any given application and can beimplemented in one or more separate or shared modules in variouscombinations and permutations. Even though various features or elementsof functionality may be individually described or claimed as separatemodules, one of ordinary skill in the art will understand that thesefeatures and functionality can be shared among one or more commonsoftware and hardware elements, and such description shall not requireor imply that separate hardware or software components are used toimplement such features or functionality.

Where components or modules of the application are implemented in wholeor in part using software, in one embodiment, these software elementscan be implemented to operate with a computing or processing modulecapable of carrying out the functionality described with respectthereto. One such example computing module is shown in FIG. 13. Variousembodiments are described in terms of this example-computing module 90.After reading this description, it will become apparent to a personskilled in the relevant art how to implement the application using othercomputing modules or architectures.

In this document, the terms “computer program medium” and “computerusable medium” are used to generally refer to non-transitory media suchas, for example, memory 96, or other memory/storage units. These andother various forms of computer program media or computer usable mediamay be involved in carrying one or more sequences of one or moreinstructions to a processing device for execution. Such instructionsembodied on the medium, are generally referred to as “computer programcode” or a “computer program product” (which may be grouped in the formof computer programs or other groupings). When executed, suchinstructions might enable the computing module 90 to perform features orfunctions of the present application as discussed herein.

While various embodiments of the disclosed method and apparatus havebeen described above, it should be understood that they have beenpresented by way of example only, and not of limitation. Likewise, thevarious diagrams may depict an example architectural or otherconfiguration for the disclosed method and apparatus, which is done toaid in understanding the features and functionality that can be includedin the disclosed method and apparatus. The disclosed method andapparatus is not restricted to the illustrated example architectures orconfigurations, but the desired features can be implemented using avariety of alternative architectures and configurations. Indeed, it willbe apparent to one of skill in the art how alternative functional,logical or physical partitioning and configurations can be implementedto implement the desired features of the disclosed method and apparatus.Also, a multitude of different constituent module names other than thosedepicted herein can be applied to the various partitions. Additionally,with regard to flow diagrams, operational descriptions and methodclaims, the order in which the steps are presented herein shall notmandate that various embodiments be implemented to perform the recitedfunctionality in the same order unless the context dictates otherwise.

Although the disclosed method and apparatus is described above in termsof various exemplary embodiments and implementations, it should beunderstood that the various features, aspects and functionalitydescribed in one or more of the individual embodiments are not limitedin their applicability to the particular embodiment with which they aredescribed, but instead can be applied, alone or in various combinations,to one or more of the other embodiments of the disclosed method andapparatus, whether or not such embodiments are described and whether ornot such features are presented as being a part of a describedembodiment. Thus, the breadth and scope of the claimed invention shouldnot be limited by any of the above-described exemplary embodiments.

Terms and phrases used in this document, and variations thereof, unlessotherwise expressly stated, should be construed as open ended as opposedto limiting. As examples of the foregoing: the term “including” shouldbe read as meaning “including, without limitation” or the like; the term“example” is used to provide exemplary instances of the item indiscussion, not an exhaustive or limiting list thereof; the terms “a” or“an” should be read as meaning “at least one,” “one or more” or thelike; and adjectives such as “conventional,” “traditional,” “normal,”“standard,” “known” and terms of similar meaning should not be construedas limiting the item described to a given time period or to an itemavailable as of a given time, but instead should be read to encompassconventional, traditional, normal, or standard technologies that may beavailable or known now or at any time in the future. Likewise, wherethis document refers to technologies that would be apparent or known toone of ordinary skill in the art, such technologies encompass thoseapparent or known to the skilled artisan now or at any time in thefuture.

A group of items linked with the conjunction “and” should not be read asrequiring that each and every one of those items be present in thegrouping, but rather should be read as “and/or” unless expressly statedotherwise. Similarly, a group of items linked with the conjunction “or”should not be read as requiring mutual exclusivity among that group, butrather should also be read as “and/or” unless expressly statedotherwise. Furthermore, although items, elements or components of thedisclosed method and apparatus may be described or claimed in thesingular, the plural is contemplated to be within the scope thereofunless limitation to the singular is explicitly stated.

The presence of broadening words and phrases such as “one or more,” “atleast,” “but not limited to” or other like phrases in some instancesshall not be read to mean that the narrower case is intended or requiredin instances where such broadening phrases may be absent. The use of theterm “module” does not imply that the components or functionalitydescribed or claimed as part of the module are all configured in acommon package. Indeed, any or all of the various components of amodule, whether control logic or other components, can be combined in asingle package or separately maintained and can further be distributedin multiple groupings or packages or across multiple locations.

Additionally, the various embodiments set forth herein are described interms of exemplary block diagrams, flow charts and other illustrations.As will become apparent to one of ordinary skill in the art afterreading this document, the illustrated embodiments and their variousalternatives can be implemented without confinement to the illustratedexamples. For example, block diagrams and their accompanying descriptionshould not be construed as mandating a particular architecture orconfiguration.

What is claimed is:
 1. A system, comprising: an image stabilizationsystem, comprising: one or more motion sensors to measure a totaldisplacement or displacement rate of an image projected by a projectorfrom an equilibrium position; and a processing unit to cause one or moreactuators of the projector to actuate an optical element of theprojector to stabilize the projected image, wherein the optical elementis actuated using at least the measured total displacement ordisplacement rate.
 2. The system of claim 1, wherein the one or moremotion sensors are to measure the total displacement of the projectedimage from equilibrium, and wherein the optical element is actuatedusing at least the measured total displacement.
 3. The system of claim2, further comprising: a memory storing a plurality of lookup tables,each of the plurality of lookup tables associated with a map to correcta respective displacement or displacement range of a projected image,wherein the processing unit causes the one or more actuators actuate theoptical element using at least a lookup table corresponding to themeasured total displacement.
 4. The system of claim 3, furthercomprising: the projector, wherein the projector comprises: a lightsource; one or more optical elements to structure light emitted by thelight source to create the image; and a projection lens to project theimage.
 5. The system of claim 4, wherein the projector comprises theimage stabilization system.
 6. The system of claim 4, wherein the one ormore actuators comprise a motor to actuate the projection lens tocorrect for the measured displacement of the projected image.
 7. Thesystem of claim 4, wherein the projector is a digital light processing(DLP) projector comprising a digital micromirror device (DMD) chipcomprising a plurality of mirrors, wherein the one or more actuators areto actuate the plurality of mirrors to correct for the measureddisplacement of the projected image.
 8. The system of claim 4, whereinthe projector is a liquid crystal display (LCD) projector comprising anLCD panel, wherein the one or more actuators are to actuate the LCDpanel to correct for the measured total displacement of the projectedimage.
 9. The system of claim 4, wherein the projector is a liquidcrystal on silicon (LCoS) projector comprising a LCoS microdevice,wherein the one or more actuators are to actuate the LCoS microdevice tocorrect for the measured total displacement of the projected image. 10.The system of claim 3, wherein the image stabilization system is athree-axis image stabilization system, wherein the one or more motionsensors measure displacement of the projected image in three axes. 11.The system of claim 1, wherein the one or more motion sensors are tomeasure the rate of displacement of the projected image fromequilibrium, and wherein the one or more actuators are to actuate theoptical element of the projector to correct for a predicted displacementof the projected image based on the measured rate of displacement. 12.The system of claim 1, wherein the one or more motion sensors are tomeasure the total displacement and the rate of displacement of theprojected image from equilibrium, and wherein the one or more actuatorsare to actuate the optical element of the projector to correct for apredicted displacement of the projected image based on the measured rateof displacement and measured total displacement.
 13. A method,comprising: using one or more motions sensors to measure a totaldisplacement from an equilibrium position of an image projected by aprojector; using at the least the measured total displacement,determining an actuation of an optical element of the projector tostabilize the image; and stabilizing the projected image by actuatingthe optical element.
 14. The method of claim 13, wherein the opticalelement is actuated based on a precalculated lookup table associatedwith a map to correct for the measured total displacement, wherein thelookup table is stored in a memory of the projector.
 15. The method ofclaim 14, further comprising: storing a plurality of lookup tables in amemory of the projector, each of the plurality of lookup tablesassociated with a map to correct a respective displacement ordisplacement range of a projected image,
 16. The method of claim 14,wherein the actuated optical element is a projection lens of theprojector.
 17. The method of claim 14, wherein the projector is adigital light processing (DLP) projector comprising a digitalmicromirror device (DMD) chip comprising a plurality of mirrors, whereinthe actuated optical element comprises the plurality of mirrors.
 18. Themethod of claim 14, wherein the projector is a liquid crystal display(LCD) projector comprising an LCD panel, wherein the actuated opticalelement comprises the LCD panel.
 19. The method of claim 14, wherein theprojector is a liquid crystal on silicon (LCoS) projector comprising aLCoS microdevice, wherein the actuated optical element comprises theLCoS microdevice.
 20. The method of claim 13, further comprising:determining if the measured total displacement exceeds a predeterminedthreshold.
 21. The method of claim 14, wherein the image stabilizationsystem is a three-axis image stabilization system, wherein the one ormore motion sensors measure displacement of the projected image in threeaxes.
 22. A method, comprising: using one or more motions sensors tomeasure a rate of displacement from an equilibrium position of an imageprojected by a projector; using at the least the measured rate ofdisplacement, estimating an actuation of an optical element of theprojector to maintain a stabilized image; and actuating the opticalelement based on the estimated actuation.